Investigating Conductivity to Predict Magnesium Addition Requirements for Struvite Precipitation in Swine Manure Slurries

Posted in: Environment by admin on January 1, 2008 | No Comments

The goal of this project was to develop a system that identified magnesium demand for struvite formation by
monitoring conductivity changes during continuous injection of magnesium chloride in several swine manure slurries. Theoretical predictions and pure solution tests provided information capable of determining the magnesium demand for struvite precipitations. However, after testing six different manures in triplicate, the conductivity responses did not follow theoretical predictions and failed to provide any indication of optimum magnesium injection rates for phosphorus removal.

For more information the full article can be found at http://asae.frymulti.com/toc.asp

Simple odor solution

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Oklahoma farmer Vic Little is constantly looking for other ways
to further reduce the odor of his hog farm, and has discovered a
solution that has turned out to be simple and inexpensive—piping
which acts as a buffer system in the lagoon.

Temperatures Within a Truck Transporting Pigs During Winter and Summer Months in Western Canada

Posted in: Prairie Swine Centre by admin on | No Comments

This study investigated the temperatures within a truck transporting pigs in western
Canada, during summer and winter months. Pigs were transported from PSC
Elstow Research Farm, and involved approximately 8 hours of travel to the Maple
Leaf plant in Brandon. The temperature conditions pigs were exposed to during
transport varied considerably between seasons and among compartments within
the vehicle, and pigs were exposed to temperatures as low as -15 °C or as high as
30 °C.

Influence of sex and castration of females on growth performance and carcass and meat quality of heavy pigs destined for the dry-cured industry

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This paper investigates the effects of sex and slaughter weight (SW) on growth performance and on carcass and meat quality characteristics. There were 6 treatments arranged factorially, with 3 classes (intact females, IF; castrated females, CF; and castrated males, CM) and 2 slaughter weights (114 and 122 kg of BW). It was found that castrated males and females at more feed, grew faster, and had more carcass backfat depth. Also, compared to intact females, CF and CM had more intramuscular fat and less linoleic acid content in the subcutaneous fat. It is concluded that CF and CM had similar productive performance meat quality characteristics when slaughtered at the same age, and that castration of females improved average daily gain and increased weight and fat content of primal cuts. Therefore, castration of females is recommended for pigs destined for the dry-cured industry because of the beneficial quality effects of the primal cuts when castrated.

Duration of dietary linseed feeding affects the intramuscular fat, muscle mass and fatty acid composition in pig muscle

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In the present study, linseed was fed to growing–finishing barrows for three different lengths of time before slaughter at 100 g/kg diet, and the dietary ALA content is calculated to 20 g/kg diet. The aim of this study was to investigate the effect of duration of dietary linseed feeding on subcutaneous carcass fat, intramuscular fat and the muscle mass. It was found that feeding a diet of 100 g of linseed/kg to pigs increased the content of n-3 polyunsaturated fatty acid in muscle and adipose tissue, stimulated intramuscular fat accumulation, and promoted the hypertrophy of the longissimus dorsi muscle, quadriceps femoris muscle mass, and semitendinosus muscle. Further research should be done to identify the effect of dietary n-3 PUFA enrichment in tissues on lipid metabolism related genes in adipose tissue and muscle, respectively.

Cash Settlement of Lean Hog Futures Contracts Reexamined

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The purpose of the paper is to reexamine cash settlement of lean hog futures contracts as a
hedging tool, focusing on basis behavior and management of basis risk. To understand the
dimensions of the situation, first we compare hog futures contract basis level, variability, and exante
basis risk measured in terms of forecast ability between physical delivery and cash
settlement using data from 1985 to 2008 on hog cash and future prices. We then examine the
hedging usefulness of the current CME lean hog index and provide an alternative hedging
instrument—a regional basis contract—that takes into account location differences between
regional cash prices and the CME lean hog index. Our results indicate that basis has widened and
its variability prior to expiration has increased in the cash settlement period. However, we find
no evidence to suggest that ex-ante basis risk has increased, meaning that the ability to forecast
basis prior to expiration has declined little with cash settlement. Routine hedging with futures
contracts as expected reduces the variability in returns compared to cash sales. Including
location differences further reduces the variability in cash prices. Our results should be of value
to users of the hog futures markets and market analysts that offer pricing advice.

Incorporating Structural Changes in Agricultural and Food Price Analysis: An Application to the U.S. Beef and Pork Sectors

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This paper proposes a protocol for agricultural and food price analysis, which goes beyond the existing practices of focusing on the time series properties of the variables in question, such as the existence of a unit root and of a
cointegrating relationship among nonstationary prices, by entertaining structural breaks when conducting those tests. Specifically, this study applies Perron’s unit root test and Gregory and Hansen’s cointegration
test (both of which allow for structural change of unknown timing) to the U.S. beef/cattle prices
and pork/hog prices. To obtain consistent estimates of the break dates in the retail beef,
wholesale beef and farm cattle price linkage equation and those in the retail pork, wholesale pork
and farm hog price relationship, the study employs Bai and Perron’s and Kejriwal and Perron’s
global sum of squares minimization procedure to search for the optimal break dates, utilizing the
principle of dynamic programming to ease the computation burden. The empirical results strongly suggest that beef/cattle prices are nonstationary, while there is ample evidence to support the conclusion that pork/hog prices are stationary.

Analysis of periparturient risk factors affecting sow longevity in breeding herds

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The association of periparturient risk factors with sow longevity and the validity of sow removal decisions made during the periparturient period were analyzed. Data pertaining to 2066 sows from a commercial breeding herd from the US Midwest were used in this study. The likelihood of removal from the herd within 35 d post-farrowing decreased with a younger parity, the absence of lameness or other health problems, a higher lactation feed intake (LFI) and a greater number of live-born piglets (P a younger parity lowered (P number of piglets born alive was higher (P periparturient period. A greater (P periparturient period farrowed. More sows (P culled compared with sows retained without health problems during the periparturient period. In summary, periparturient factors such as LFI, the incidence of lameness or health problems, as well as sow-level characteristics such as higher parity and fewer piglets born alive predicted the removal of a sow from the breeding herd. Sows retained with periparturient health problems had reduced longevity and fewer live-born piglets, and fewer such sows had another farrowing.

For more information the full article can be found at http://jas.fass.org/

A note on the effects of co-mingling piglet litters on pre-weaning growth, injuries and responses to behavioural tests

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Two coping styles, ‘‘active’’ and ‘‘passive’’, are well defined for some species (see Koolhaas et al., 1999 for a review). Even though the existence of distinct coping styles in pigs is controversial (Jensen et al., 1995), studies on coping abilities have provided insights into piglet behaviour (Hessing et al., 1993; Ruis et al., 2001). Behavioural tests have been used to identify possible behavioural patterns indicative of coping styles. Hessing et al. (1993) introduced the backtest as a general assessment of pigs’ coping styles. According to Benus et al. (1991) passive copers are less social, less aggressive and show longer attack latencies than active copers. Consequently, social challenges, in which piglets are allowed to interact with unfamiliar individuals (D’Eath and Burn, 2002) and social isolation tests (Ruis et al., 2001) have been used as indicators of pigs coping styles. In pigs, the effects of co-mingling litters on coping abilities before weaning are unclear. Thus, the purpose of this study was to determine how co-mingling litters affected piglets’ pre-weaning growth, ear injuries, suckling behaviour and responses to behavioural tests used to measure coping abilities. Thirty sows and their respective litters were housed in standard farrowing crates until day 13 after birth. On day13, the partition between two neighbouring pens was removed for 20 litters allowing piglets to interact (forming 10 co-mingled litters). The remaining 10 control litters were kept in standard farrowing crates throughout the experiment. Three focal piglets from each litter were used for data collection. Focal piglets were weighed and ear injuries recorded on days 2, 4, 9, 12, 15 and 18 after birth. There were no differences in piglets’ weight gain before or after co-mingling. Ear injuries were more abundant in co-mingled litters on day 15 (P < 0.05) but these differences disappeared by day 18. Suckling behaviour was recorded on days 5, 8, 10, 14, 16 and 18 after birth. There were no differences in teat fidelity, suckling frequency and mother fidelity between treatments. Three behavioural tests, social challenge, isolation, and backtest, were performed before and after co-mingling. There were no treatment effects on piglets’ response to the isolation test and backtest. Co-mingled piglets showed longer latency for the first aggressive interaction (P < 0.05), spent more time in proximity to one another (P < 0.05) and performed less single bites (P < 0.05) than control piglets during the social challenge. In addition, the duration and frequency of aggressive interactions (P < 0.05) were lower in co-mingled piglets than control piglets. Co-mingling did not affect the frequency of single head thrusts or oral–nasal contact, but did tend to increase the frequency of escape attempts (P < 0.10). Our results suggest that co-mingling litters during lactation affects piglets’ social behaviour, by primarily decreasing aggressive interactions during social challenges.

For more information the full article can be found at http://journals.elsevierhealth.com/periodicals/applan/issues

Effects of space allowance on the welfare of dry sows kept in dynamic groups and fed with an electronic sow feeder

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The minimal legal space allowance for grouped pregnant sows in the EU is 2.25 m2/sow. The effect of higher
space per animal on agonistic behaviour and social stress of animals living in dynamic groups is not known.
Two groups of 34 pregnant Belgian Landrace sows were housed in two pens of respectively 102 m2 (3 m2/
sow) and 76.5 m2 (2.25 m2/sow). Each sow lived there for 15 weeks. Sows were fed through an electronic sow
feeder. According to the dynamic system, one third of each group (i.e. 11 or 12 nearly parturient sows) was
replaced every 5 weeks by the same number of recently inseminated sows.Welfare indicators were collected
during six of these 5 week-periods: performance, agonistic behaviour, skin lesion score and salivary cortisol.
No differenceswere observed for production parameters, or for fighting activity. However, themean number of
one-way aggressions, when observed during 2 h-periods at 3 and 8 days after grouping, was significantly lower
in the large pen than in the small one (respectively 16 X 2 versus 26 X 3, p < 0.01, and 10 X 2 versus 20 X 5,
p < 0.05). The mean number of injuries was also lower with the 3 m2 space allowance, when collected on the
introduced sows one, 2 and 3 weeks after grouping. Some contradictory differences in salivary cortisol were
noted 2 and 26 h after mixing, but without reaching statistical significance. An available area 33% higher than
the EU legal minimum reduced agonistic behaviour and consecutive wounds and thus induced better welfare
conditions for sows living in dynamic groups and fed with an electronic sow feeder. The impact on productivity
and social physiological stress need further research.

For more information the full article can be found at http://journals.elsevierhealth.com/periodicals/applan/issues